Based on the spec I'd guess that the Lenovo would blow the Dell out of the water in terms of battery life. I tend to prefer Lenovo's keyboards as well. The H processor in the Dell and the P600 use like double the watts, and should have to either run hotter, or louder (cooling fans), then the Lenovo. However, I might try and get something with a 1050ti, even the P600 won't get you stellar gaming performance. The 50% increase in performance to a 1050 would make the difference between meeting the Darksouls III minimum system requirement, for example. It really depends of course on your gaming needs.